NOACS, Watchman Device Cost-Effective for Stroke Prevention

For stroke prevention in patients with atrial fibrillation, left atrial appendage closure (LAAC) with the Watchman device (Boston Scientific, Marlborough, MA) and nonwarfarin oral anticoagulants (NOACS) are cost-effective relative to warfarin, but LACC was also found to be cost-effective and offer better value relative to NOACS, according to research published in the Journal of the American College of Cardiology.

In the US, Medicare spends an estimated $16 billion annually on atrial fibrillation (AF) and AF-related stroke. While warfarin has been the standard of care for stroke prevention in patients with AF, it is also associated with increased bleeding risks, nonadherence, and lower quality of life (QoL).

To analyze the cost-effectiveness of 3 major treatment strategies—LAAC with the Watchman device, NOACS, and adjusted-dose warfarin— researchers developed a Markov model in Excel, constructed from the perspective of the Centers for Medicare & Medicaid Services, with a 20-year lifetime horizon. Data from PROTECT AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients with Atrial Fibrillation) served as primary sources for clinical event rates and outcomes.

Cost-effectiveness was determined using the US accepted willingness-to-pay threshold of $50,000 per quality-adjusted life-year (QALY) gained, and reported as incremental cost-effectiveness ratio (ICER).

As researchers anticipated, LAAC was more expensive than warfarin in the first year post-procedure and patients had fewer QALYs. By the third year, LACC patients' QALYS were higher than warfarin patients, and by the seventh year, LAAC became cost-effective relative to warfarin. After a decade, LAAC became more effective and less costly and continued through the 20-year time horizon.

NOACS were more effective than warfarin during the first year and became cost-effective relative to warfarin at 16 years ($48,446/QALY). However, NOACS were not cost saving relative to warfarin over the 20-year span, but the ICER continued to decrease, resulting in a $40,602 cost per QALY at the 20-year mark.

Again, as expected, LAAC was more expensive than NOACS in the first post-procedure year. By the fifth year, however, LAAC was less expensive ($20,892 vs $20,924) and more effective (3.455 vs 3.448 QALYs) than NOACS. LAAC remained more effective across the lifetime horizon.

“When compared over a lifetime, LAAC proved to be the most cost-effective treatment,” researchers concluded. “For stroke prevention, the risk and cost of stroke are highly important, but so too are QoL and functional outcomes following stroke. Indeed a preference study of stroke outcomes revealed that most patients rate severe disability as worse than death.”

To that end, LAAC-treated patients experienced fewer disabling strokes compared with patients who took warfarin. Most strokes (79%) that occurred in LAAC-treated patients resulted in modified Rankin scores between 0 to 2 vs patients who took warfarin (24%) or patients who took NOACS (44%).

“This finding suggests that most LAAC-treated patients can return to daily life without assistance following stroke, whereas more than one-half of the patients who have a stroke while taking oral anticoagulants require lifetime assistance,” researchers wrote.